Introduced version 2.28 with first preliminary implementation of traceelement turnover between soil solution, plant and organic material in the soil. The trace element is introduced in the Salttracer module. The general switch is TraceElementUptake. In addition to this the ActiveUptake switch regulates an uptake of traceelement that is related to the demand of carbon of the plant. Three parameters ActiveUptEffLeaf, ActiveUptEffRoots, ActiveUptEffStem controls the uptake to the three respectively components of the plants. When the concentrations are below a certain threshold specified with the parameter ActiveUptMaxEffConc a linear reduction of the uptake rate is applied. A passive uptake approach that follows the water flow is associated to the switch PassiveUptake. The demand is proportional to the water uptake by the plants and scaled by the parameter PassiveUptScaling. The allocation to leaf, stem and roots is related to the respectively parameters: PassiveUptAlloLeaf and PassiveUptAlloStem.
In the plant and in the soil the traceElement is following the carbon fluxes, except that no volatilisation is allowed. Another exception is that no harvest is applied to the traceelement. A number of state variables, fluxes and auxiliary variables are introduced.
A new switch InitialSaltConcentrations allows for uniform or distributed initial conditions of salt in the soil. PEJ